PARIS - Fine French Restaurant Recommendations?

[YRRunner]

We are going to the Prix D'Arc horse racing 1st weekend in October and are struggling to find a minimum 2 star Michelin restaurant that you do not need to book 6 months in advance. Is it really that difficult to find a table in a top restaurant in Paris for goodness sake? Any recommendations much appreciated. We are staying at the Ampere, close to the Champ Elysees, about a 1/2 mile from the Arc D'Triomphe.